1. Technical Field
This disclosure relates to data storage systems, such as solid state drives, for computer systems. More particularly, the disclosure relates to lower page data recovery.
2. Description of the Related Art
Memory arrays with multi-level cell (MLC) NAND media are now commonplace in solid state drives (SSDs). MLC allows multiple possible states to exist in a single memory cell, thereby enabling the storing of more than one bit of information per cell (e.g., 2, 3, 4 or more). For example, in a 2-bit-per cell MLC flash, 4 possible states (4 voltage (Vt) levels) are possible which enable storage of 2 bits. Based on the data the memory cells are going to store and the coding for different states, the cells are programmed to 4 possible and distinctive Vt zones. Typically, data stored in lower pages and upper pages are logically paired together, with the lower pages being programmed first.